PIN Diodes: Very useful for aligning and measuring transmission. In a small package for easy positioning (slim-pin).

This is a Hamamatsu PIN diode encased in black delrin plastic (90x20x4mm). At the base is an aluminum block that allows it to mount to a Newport post. The diode is electrically insulated at the front by a kapton film, shielded at the back by lead tape and wrapped all over by aluminum foil to block visible light. Blue tape is for color coding. Click photos to enlarge.